LibreSSL. Multiple issues were addressed by updating to libressl version 2.6.4.

x509/x509verify.c in LibreSSL before 3.4.2, and OpenBSD before 7.0 errata 006, allows authentication bypass because an error for an unverified certificate chain is sometimes discarded.

LibreSSL. Multiple issues were addressed by updating to libressl version 2.6.4.

LibreSSL 2.9.1 through 3.2.1 has an out-of-bounds read in asn1itemprintctx (called from asn1templateprintctx).

LibreSSL 2.9.1 through 3.2.1 has a heap-based buffer over-read in doprintex (called from asn1itemprintctx and ASN1itemprint).

LibreSSL 2.5.1 to 2.5.3 lacks TLS certificate verification if SSLgetverifyresult is relied upon for a later check of a verification result, in a use case where a user-provided verification callback returns 1, as demonstrated by acceptance of invalid certificates by nginx.

An issue was discovered in x509/x509verify.c in LibreSSL before 3.6.1, and in OpenBSD before 7.2 errata 001. x509verifyctxaddchain does not store errors that occur during leaf certificate verification, and therefore an incorrect error is returned. This behavior occurs when there is an installed verification callback that instructs the verifier to continue upon detecting an invalid certificate.

LibreSSL before 2.6.5 and 2.7.x before 2.7.4 allows a memory-cache side-channel attack on DSA and ECDSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover a key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.